LibWeb: Ensure transform of SVG <use> updates with x and y attributes

Rather than modify the transform of the parent (which could change
independently), this adds a new override element_transform() where
element specific tranfroms can be applied. This will always stay in
sync with the attributes.

A ref test comparing a .svg and .html version of the same file is
added as due to differences in attribute parsing order, the .svg version
was previously drawn incorrectly.

Fixes #20859

Tests/LibWeb/Ref/manifest.json

@@ -17,5 +17,6 @@
     "svg-gradient-spreadMethod.html": "svg-gradient-spreadMethod-ref.html",
     "svg-radialGradient.html": "svg-radialGradient-ref.html",
     "svg-symbol.html": "svg-symbol-ref.html",
-    "border-radius-shrink-zero-sized-box.html": "border-radius-shrink-zero-sized-box-ref.html"
+    "border-radius-shrink-zero-sized-box.html": "border-radius-shrink-zero-sized-box-ref.html",
+    "svg-file-matches-html-file.svg": "svg-file-matches-html-file.html"
 }

Tests/LibWeb/Ref/svg-file-matches-html-file.html

@@ -0,0 +1,13 @@
+<style>
+  * {
+    margin: 0;
+  }
+</style>
+<svg xmlns="http://www.w3.org/2000/svg">
+  <defs>
+    <g id="10">
+      <rect width="50" height="50" fill="#555555"></rect>
+    </g>
+  </defs>
+  <use href="#10" x="25" y="25"></use>
+</svg>

Tests/LibWeb/Ref/svg-file-matches-html-file.svg

@@ -0,0 +1,8 @@
+<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg">
+  <defs>
+    <g id="10">
+      <rect width="50" height="50" fill="#555555"></rect>
+    </g>
+  </defs>
+  <use href="#10" x="25" y="25"></use>
+</svg>